Currently, various tools are proposed for a medical treatment tool which is inserted into a body cavity by inserting through a treatment tool channel of an endoscope, so as to perform a predetermined treatment such as ligation and suture on a biological tissue, and obtain a biological sample. As a medical treatment tool of this kind, for example as disclosed in Japanese Unexamined Patent Application, First Publication No. 2003-204966 (paragraph Nos. 0046 to 0061, FIGS. 9 to 14), there is known a medical ligation unit capable of ligating an affected part in the body cavity by a ligation wire, and cutting the ligation wire that performs the ligation, by a series of operations.
This medical ligation unit comprises a medical ligation tool which is anchored in the living body, and an operating device which performs a ligation operation by guiding the medical ligation tool into the body. The medical ligation tool has the aforementioned ligation wire which has a folded portion on the proximal side, and a fixing member which fixes the ligation wire in a back-and-forth movable manner, ahead of the folded portion. The fixing member comprises a first member and a second member.
The first member is formed in a cylindrical shape, and has a press-fit portion provided on the distal side, and a large diameter portion having annular cutting blades provided on the proximal side. On the peripheral face of this large diameter portion is formed coupling catches. Moreover, the second member has; a fixing hollow which is arranged so as to be movable back-and-forth in the distal side of the first member formed in a cylindrical shape, and into which the press-fit portion is press-fitted, and coupling holes provided in the periphery of the cylindrical portion, and capable of coupling with the coupling catches.
Moreover, the ligation wire is passed from the distal end of the second member, through the fixing hollow, and comes out from the side holes of the cylindrical portion to the outside, and is then guided from the wire guide provided on the proximal side of the large diameter portion of the first member to the inside, so as to become the folded portion.
The operating device has an inner sheath which is in contact with the proximal side of the second member. The proximal side of the inner sheath is connected with an operation portion main body having a finger catch ring. Moreover, the operation portion main body is attached with a slider which is back-and-forth movable with respect to the operation portion main body. The slider is connected with an operation wire, which is inserted through the inner sheath, and has a coupling member on the distal end. This coupling member is designed to be coupled with the folded portion of the ligation wire. That is, by operating the slider back-and forth while the operation portion main body is fixed, the diameter of the ligation wire can be expanded or reduced.
In the case where an affected part in a body cavity is ligated by the medical ligation unit constituted in such a manner, the medical ligation unit is inserted into the body cavity via an endoscope device or the like, and the ligation wire is hooked on the affected part.
In this condition, the operation portion main body is fixed, and the slider is moved in the proximal direction, so as to move the operation wire backward. As a result, the ligation wire is pulled into the second member, and hence the diameter of the ligation wire is reduced. By so doing, the affected part is tightly bound, and the blood flow can be stopped. Moreover, since the affected part is pulled to the second member side by further pulling the operation wire, the second member is pushed to the first member side via the affected part. By the movement of the second member, the press-fit portion of the first member is relatively moved into the fixing hollow. Consequently, the ligation wire in the fixing hollow is held and fixed between the inner face of the fixing hollow and the outer face of the press-fit portion. Moreover, the ligation wire is cut by the cutting blades of the first member, on the clamped proximal side. Furthermore, at this time, the coupling catches are engaged into the coupling holes, so that the first member and the second member are mutually coupled.
As described above, after the affected part is tightly bound, the second member is moved toward the first member via the affected part, so as to couple both members. At the same time, the ligation wire is held and fixed between both members, and the ligation wire is cut rearward of the holding position, thus completing the ligation treatment.
The present invention takes the above problems into consideration with an object of providing a medical treatment tool capable of fixing and cutting a wire such as a ligation wire, without involving the biological tissue, after a predetermined treatment on the biological tissue.